Burning of explosive gaseous mixtures.



c. E. LUCKE.

BURNING 0F EXPLOSIVE GASEOUS MiXTURES.

APPLICATION FILED JULY 10, I9I5.

1 ,30 ,8 1 9.. Patented May 6, 1919'.

TS-$H [ET I A MAtty C. E. LUCKE.

BURNING 0F EXPLOSIVE GASEOUS MIXTURES. APPLICATION FILED JULY 10, I915.

1 .309%1 9 Patented May 6, 1919.

2 SHEETS-SHEET 2.

b Mam UNITED STATES PATENT OFFICE,

" cnAnLEsE. LUCKE, or NEW YORK, N. Y., Assrenort TO GAS morn oomnus'rron COMPANY. OF NEW YOBI KQN. Y., A CORPORATION OF DELAWARE.

BURNING OF EXPIlOSIVE GASEOUS MIXTURES.

To all whom it may concern: 1

Be it known that 1, CHARLES E. LUGKE, a citizen of the-United States, residing at New York city, in the county of New York and State of New York, have invented certain.

new and useful Improvements in the Burning of Explosive Gaseous Mixtures, fully described and represented in the following specification and the accompanying draw-' flow velocity reduced by being baffled and caused to spread out'against a directing and confining surface, and is burned where its reduced velocity is equal to the rate of propagation of inflammation of the mixture and the invention comprises also apparatus for practising the method, including means for supplying'the mixture flowing with the necessary excess velocity, and baffling means for causing the desired controlled reduction of flow velocity of the mixture; all as hereinafter more fully described and as claimed.

Continuous and localized combustion of explosive gaseous mixtures is accomplished in two ways: first,'by feeding the mixture through a flame-interrupting coooling pas 'sageway or screen at a rate'low enough to cause its exit velocity to'be lessthan the rate of propagation of inflammation' of the mixture and then burning the mixture atthe exit side of the screen; and second, by caus ing the mixture to flow with a velocity greater than the rate of propagation of inflammation of the mixture inorder to prevent back-flashing, and then, to prevent ,blow-oii or the carrying away of the flame,

reducing the velocity to the rate oi? propagation of inflammation while preventing dissipation of the mixture or diifusion with other gas, and burning the mixture at the surface at which the-velocity becomes equal to the rate of propagation of inflammation. The present invention relates to the second way of securing continuous and localized combustion of explosive gaseous mixtures, which is the most eflicient way, and for most purposes the most advantageous.

Specification of Letters Patent.

The object of the invention is to provide an improved method and apparatus for .de-' veloping heat by burning explosive gaseous mixtures which shall be simple and shall be generally adaptable for use under widely varying conditions and shall meet the requirements for maintaining continuous com- Lbustion localized within narrow limits of explosive mixtures of varying rates of inflammation and supplied under varying pressures or at varying velocities. Among Patented May 6, 1919.

\ L Application filed July 10, 1915. Serial 110,139,069.

the special objects of the invention may be mentioned that of securing the required .reduction'. of velocity of the inflowing mixture with a minimum of resistance, thereby minimizing the required supply pressure, se-

curing the localization of the combustion in,

or approximately in a desired plane under varying pressures, securing the quick attainment of normal operation with a large amount of the developed heat supplied in the form of radiant heat, the reduction in the thickness of that part of the burner structure which lies beyond-the discharge openings of the mixture supply passages, and the provision of a burner which is well adapted for use in any desired position.

Other objects and advantages of the invention will appear from the following; de-

scription.

In burnlng explosive gaseous mixture in accordance with the present invention, the

mixture is caused to flow, in one or a number of suitably spaced streams, with a velocity greater than the rate of propagation of inflammation of the mixture, and the flow velocity is then reduced by bafliing the stream of mixture and causing it to spread outwith increasing cross-section and with rapidly decreasingyelocity' against the bafi ling surface. and, most desirably, between it and a closely adjacent coacting wall.

' The reduction of the flow velocity to the rate ofpropagation of inflammation so that com- .bustion may take place at the surface where equality between the flow velocity of the mixture and the rate of propagation of inture. The bafiling surface will usually be a:

comparatively. thin plate of impermeable I and highly refractory material, so that, the

flammation of the mixture is attained is thus secured within a comparatively short displate becoming highly heated, its outer sur face may serve efiiciently as a source of radiant heat. Such plate should be made of material substantially permanent and not too fragile, such as non-oxidizable or slowly oxidizable metal like nickel, nickel steel, chrome nickel, etc., for the more moderate temperature operations, orsuitable porcelain, silica, clay, alundum, etc., for the higher temperature operations. permeable bafiiing plate or wall, that is, one which will not permit passage into and through it of any substantial part of the gaseous mixture flowing against it, .the spreading out and reduction of flow velocity of the mixture to the required degree against the face of the plate or wall and the localized action of the combustion adjacent to the surface of the bafiiing plate or wall may be secured under wide variations in the supply velocity of the mixture and under. velocities very greatly in excess of the rate of propagation of inflammation. The bafliing wall may therefore be made in the form of a very thin plate, the limitation of thinness being only that imposed by the necessary strength of the plate. The thinner the bailiing plate, the quicker it will become heated to the maximum degree after combustion is started. If the mixture is supplied in a single stream, the combustion gases may escape beyond the edges of the baffling plate or through openings therein beyond the limit of spreading of the mixture required to secure the necessary reduction of velocity. If the mixture is supplied in a plurality of streams, such streams should be suitably spaced, and the baiiiing plate, which may be a single integral plate or may be formed by a plurality of parts suitably joined or relatively positioned, may be formed with openings of suitable capacity suitably located between the portions of the plate against which the streams of mixture spread out.

The co-acting wall which is preferably provided closely adjacent to the bafliing surface may also be a thin plate adapted to serve as a source of radiant heat, but will usually be a suitable impermeable wall of low heat conductivity so that heat received by it from the combustion space will be de fiected back toward the baflling plate. the heat generated being thus substantially all sup-plied in the direction away from the outer or far side of the bafiling plate. I have found that best results are secured by having the co-acting faces of the bafliing plate or wall and such adjacent wall approximately parallel and so close together that the mixture will completely fill, or extend all the way across, the space between them as it advances with decreasing velocity. Access of the atmosphere or other gases to the spreading mixture is thus entirely prevented, and the mixture is positively di- By using an -im' surface and also to some extent to prevent or limit the access of the atmosphere to the spreading mixture, or the wall-might even be entirely removed.

It will be understood that by the term explosive gaseous mixture as used herein is meant a mixture of a suitablecombustion supporting gas, either oxygen aloneor airor other oxygen-containing gas, with combustible matter in a gaseous or other finely divided state in proper proportions, that is, in proportions such that the mixture will have the property of self-propagation of inflammation. For producing the highest temperature, the oxygen should be undiluted I and the mixture should contain oxygen and combustible matter in chemical combining proportions at the time of combustion; but there may be an excess of either the combustible matter or the combustion supporting gas within the limits which determines the property of self-propagation. The mixture may be varied in this respect according to the desired character of the products of combustion, that is, whether it is desired that the products shall be neutral, oxidizing or reducing. Also, the mixture may of course contain neutral gas such as nitrogen, carbon dioxid or water vapor, so long as the amount of such neutral gas is not sufficient to make the mixture non-explosive.

The accompanying drawings show simple forms of apparatus whereby the method may be practised and which embody the apparatus features of the invention. In said drawings:

Figure 1 is a sectional view of a small furnace of simple form heated by the combustion of'mixture supplied through a single supply passage;

1g. 2 is a section taken on line 22 of Fig. 1;

Fig. 3 is a sectional view of a burner having a plurality of mixture supply passages;

Fig; 4 is a plan view of the burner shown in Fig. 3;

Fig. 5 is a sectional view of a burner similar tothat shown in Fig. 3, but having a modified form of bafiling plate and having a heat-equalizing and radiating screen beyond the plate;;

Fig. 6 is a plan view of the burner shown in Fig. 7; v

in Fig. 5 with the heat-equalizing and radi ating screen removed;

Fig. 7 is a diagrammatic sectional view of a single jet burner similar to that of the furnace shown inFig. 1, but on a larger scale; Fig.8 is a plan view of the burner shown Fig. 9 is a view similar ,to Fig. 7 but showing the bafliing plate set farther from the hearth; and I Figs. 10, 11, 12 and 13 are diagrammatlc sectional views of other modified forms of .excess velocity from any suitable source or i by any suitable means, as forexample by the means shown in Fig. 3 for supplying a mixture of fuel gas and air. Mounted adjacent.

the hearth within the furnace chamberand extending over the mixture inlet opening and spaced slightly away from the face of the hearth isa baflling plate 14: of suitable highly refractory material such as alundum. The bafliing plate, unless otherwise formed to provide for escape of the combust on gases from beneath it, should be of such slze as to leave anopening'around its edge. It may be supported. in any suitable manner, as by supporting and positioning lugs 15,'as shown. g p

The mixture supplied through the passage rate of propagation of inflammation of the mixture strikes the under side of the plate I 14 and is thereby caused to spread out and to advance with increasingcross-sectionand with decreasmg veloclty'inthe space between the plate and the hearth. The flow velocity of the mixture is thus rapidly reduced, and reduction of velocity to the rate of propagation of inflammation of the mixture belng attained before the mixture passes beyond the edges of the plate, combustion-will take. place adjacent the plate and in the space between it and the hearth.

The portions of the plate adjacent to which combustion of the mixture takes place become quickly heated to a high state of mcandescence, and the extremely hot combustion gases pass out from beneath the plate into the furnace chamber. heating to a high state of incandescence all the interior surfaces of the furnace chamber swept by these hot gases. 4

The plate should be spaced oif from the hearth a suflicient distance to permit the mixture to flow outward from the baflling point as fast as it can be supplied through the passage 13, and it is most desirably set close enough to the hearth so that the advancing mixture will 'fill, or extend all the way across, the space between the plate and the hearth. I consider it best to have the plate set off from the hearth a distance about equal to one-quarterof the diameter of the supply passage, assuming the supply passage to be around passage. When so set the flow capacity of the space immediately adjacent the edges of the passage will be equal to that of the passage. When the plate is set so closely adjacent to the hearth that the advancing mixture fills the intervening space, successive surfaces of uniform velocity of the mixture as it advances between the plates will be in the form of nar row bands extending about the point of impact of the stream against the baliling plate, as indicated by the dotted lines a and b in Figs 7 and 8, and the combustion of the mixture will be completeat such surfaceof uniform velocity at which the. velocity is equal to the rate of propagation of inflam 'As the plate be mation of the mixture. comes highly heated some combustion of the mixturev probablyoccurs against the surface of the plate within the line or zone where equality between the flow velocity and the rate of propagation .of inflammation is attained, but the combustion will principally occur at such band. or surface where the flow velocity equals the rate of propagation of inflammation. Whenthe plate is set parelle'l to the hearth and 1 to extend at right angles to thedirection in which the stream of mixture strikes against it, the spreading .of.the ,mixturebetween the plate-and hearth 13 moving with a velocity greater than the will, in the absence of other disturbing con dition's, be substantially uniform in all directions. and the successive surfaces of uni-- form velocity will be in the form of annular bands. As the plate and hearth become highly heated, the rate of combustion and capacity of the burner is increased by the heating of the advancing mixture and also,

it is believed, by the presence of the incanture in which the mixture is supplied in a plurality of suitably spaced streams. This burner as shown comprises a burner head comprising a cup shaped casing 30 and a filling 21 of suitable highly refractory material of low heat conductivity, a casing or header 22 providing a supply chamber, and a plurality of connecting members 23 ex tending between the. burner body and the header 22 and through which the supply passages 13 extend from the supply chamber ing 21.

to and through the hearth or refractory 'fill- The casing or header 22 is provided with an inlet 25 through which the explosive mixture is supplied to maintain the mixture in the supply chamber under a pressure sufficient to cause the mixture to flow through the supply passages 13 with the desired excess velocity. The mixture supplying means shown comprises a tank G for fuel gas and a tank A for air or oxygen or other combus tion supporting gas. The fuel gas.and combustion supporting gas may be supplied to these tanks by any suitable means adapted to maintain the desired pressures therein. Outlet pipes controlled by valves a and 9 lead from the tanks and connect with a supply pipe 26 which leads to the inlet 25, of the supply chamber. The valves a and 9 Serve to control the proportions of fuel gas and combustion supporting gas in the mix-' ture, and the pressure maintained in the supply chamber and the velocity of flow through the supply passages 13 may also be controlled by these valves. The proper proportions of fuel gas and combustion supporting gas, that is, proportions such according to the nature of the constituent gases that the mixture shall have the property of self-propagation of inflammation. maybe readily determined by experiment. The means shown and above described for supplying an explosive mixture under the required pressure is, of course, only illustrative, and various other suitable means might be employed. So also, explosive mixtures other than mixtures of fuel gas and air or other combustion supporting gas may be used in practising my method, such. for example, as explosive gaseous mixtures of air and coal dust or charcoal dust or fine oil spray, 'mist'or fo'g.

The baliling plate 14* extends adjau-eut the hearth past the discharge openings of the several supply passages 13, being supported y a peripheral support or shoulder filllllO-(l on the hearth or otherwise. The portions of the plate opposite the supply passages are impermeable, but between such impermeable bafliing portions, which should be of sufficient extent to efi'ect the desired reduction of the flow velocity of the streams of mixture striking against them, the plate has openings 27 for the escape of the combustion gases. The plate is most desirably'spaced off from the face of the hearth a distance such that the spreading mixture will fill or extend clear across the space between the plate and the hearth as explained in connection with Figs. 1 and. 2. In order to increase the proportionate amount of heat supplied in the form of radiant heat, the baffling plate is made as thin as the necessary strength will permit and of a suitable refractory material of high heat conductivity combustion being maintained within the supply chamher, the mixture flows through the supply passages 13 with a velocity in excess of the rate of propagation of inflammation of the mixture and h stream of mixture leaving its supply passage is bafiled and caused to spread out against the bafiling plate and between it' and the hearth with reduction of flow velocity in 'the'same manner as in the case of the single stream burner shown in Figs. 1, 2 and 7. The baflling plate becomes highly heated by the combustion adjacent its under face, and because of its high heat conductivity it will, if the burner is suitably proportioned, become highly incandescent throughout its whole or substantially its whole extent, serving as a highly eflicient source of radiant heat.

Figs. 5 and 6 illustrate a form of burner similar to that shown in Figs. 3 and 4 except that instead of a single integral bafiling plate formed with openings for the esca e of the combustion gases, the plate 14 is formed of a plurality of parts or sections (Z shaped to fit together to form a complete plate. each section providing the bafiling surface for a single stream of mixture in the particular form shown and the sections being formed so that when assembled the plate will have th necessary openings for the escape of the combustion gases. The several plate sections may be supported when in position in any suitable manner, as by the peripheral shoulder 28 and intermediate supporting studs 29 formed on the hearth as shown. lVith such a plate the possibility of warping under the intense heat to which the plate is subjected is practically avoided. Such plate sections will usually be molded fropi a suitable refractory cementitious materla lVhcn the plate is formed, either in sectlons or as a. single integral plate, from material which is not i. good conductor of heat. the plate will not become uniformly heated by the combustion taking place beneath it, and it is desirable in some cases to provide a heat equalizing and radiating screen spaced off somewhat from the baffling plate so as to be heated by radiant heat from the baflling plate and by the hot combustion gases. The screen should be formed so asto allow the passage through it of the gases and may be of any suitable character, such as a plate of suitable metal formed with multiplicity of small openings or perforations or a. screen woven from suitable wire. Such a screen is shown at 30 in Fig.

Fig. 9 illustrates a burner in which the and spread out against the face of the plate without beingv confined between the plate and a co-acting wall. Figs. 10, 11, 12 and13 show several illustrative variations in the v heat-conducting walls.

forms of baffling means and co-actin-g'non- What is claimed is:

1-. The method of burning'explosive gaseous mixtures which consists in supplying the mixture with a velocity greater than the rate of propagation of inflammation of the mixture, reducing the flow velocity of the mixture by baflling the stream of mixture and causing it to spread out and to advance with increasing cross-section and with decreasing velocity in an open space between directing and confining walls, and

burning the mixture where the reduced velocity is equal to the rate of propagation of inflammation of the mixture.

2., The method of burning explosive gaseousmixtures which consists in "driving a stream of the'mixtu're at a velocity greater than the rate of propagation of inflammation of the mixture against a bafliing surspread out against the baflling surface and to advance with increasing cross-section and with decreasing velocity in an' open space between closely adjacent facing surfaces, whereby the velocity of the mixture is reduced to the rate of propagation of inflammation in a narrow zone or surface extending about the bafliing point, and burning the mixture at such .zone where the velocity of flow equals the rate of propagation of inflammation.

.3. The method of burning explosive gaseous mixtures which consists in supplying the mixture with a velocity greater than the rateof propagation of inflammation of the mixture, reducing the flow velocity of the mixture by bafliing the stream of mix- 7 ture against an impermeable directing and confining wall and thereby causing it to spread outagainst'the bafliing surface and to advance with increasing cross-section and with decreasing velocity, and burning the mixture where the reduced velocity is equal to the rate of propagation of inflammatio of the mixture.

.4. The method of burning explosive gaseous mixtures which consists'in supplying rate of propagation of inflammation of the mixture, reducing the flow velocity of the mixture bybng the stream of mixture against an impermeable directing and confining wall and thereby causing it to spread out against the bg-surface and to advance with increasing cross-section and with decreasing velocity, preventing access of-the atmosphere to the spreading mixture,- and burning the mixture where the velocity is equal to therate of propagation .of inflammation of the mixture. r

5. The method of burning explosive gaseous mixtures which consists in supplying the mixture with a velocity greater than the rate of propagation of inflammation of the mixture, reduclng the flow velocity of the burning the mixture Where the velocity is equal to the rate of propagation of inflammation of the mixture, and preventing escape of heat from the space where combustion takes place in the direction away from the 'baflling surface of the directing and confining wall.

. ,6. The method of producing heat which consists in mixing a fuel in a finely divided state with a combustion supporting gas in proportions to form an explosive gaseous mixture, driving the explosive mixture thus formed at a velocity greater than the rate face, and causing the baflled stream to of'propagation of inflammation of the mix.-

ture is caused to spread out laterally and to advance with increasing cross-section and' with decreasing velocity between the bafliing plate and a coacting directing and confining wall extending closely adjacent thereto, and burning the mixture where the velocity is equal to the rate of propagation of inflam- 7 mation of themixture.

,7. The method of producing heat which consists in mixing a fuel'in a'finely divided state with a combustion supporting gas in proportions to form an explosive gaseous mixture, driving the explosive mixture thus formed at. a velocity greater than the rate of propagation of inflammation of the mixture against the surface of an impermeable bafliing plate heated to a state of incandescence, whereby the mixture is caused to 'spreadout laterally and to advance with increasing cross-section and with decreasing a 'velocity against the baflling' plate, and burning the mixture adjacent the surface of the baflling plate and thereby maintaining the plate in a state of incandescence to serve as a source of radiant heat. the mixture with a velocity greater than the v 8. Apparatus for'burning explosive gaseous mlxtures, comprising means for supplying a stream of the mixture moving with a velocity greater than the rate of propagation of inflammation of the mixture, means providing a baffling surface adapted to cause i the stream of mixture to spread out against the baffling surface, and means provlding a surface facing the baflling surface and closely adjacent thereto to 'co-act therewith to direct and confine the advancing mixture,

whereby the mixture is caused to advance between said surfaces with increasing crosssection and with decreasing velocity, the width of the space betweensaid surfaces being such that the mixture will fill said space as it advances with decreasing velocity.

9. Apparatus for burning-explosive gaseous mixtures, comprising means for supplying a stream ofthe mixture moving with a velocity greater than the rate of propagation of inflammation of the mixture, means providing a baffling surface adapted to cause the I stream of mixture to spread out against the baffling surface, said bafflingsurface lying in a plane perpendicular to the direction in which the stream of mixture moves against it, and means providing a surface facing the 7 tion of inflammation of the mixture, a bafthe atmosphere thereto.

fling plate against which said stream impinges and by which it is caused to spread out and to advance with increasing crosssection and with decreasing velocity against the plate, and a wallof low heat conductivity extending opposite the bafliing surface of the baflling plate and closely adjacent thereto to co-act therewith to direct and confine the advancing mixture and 11. Apparatus for burning explosive gaseous mixtures, compr1s1ng means for supplying a stream of the mixture moving with a-velocity greater than the rate of propagation of inflammation of the mixture, a thin baffling plate against which said stream impinge's and by which it is caused to spread out and to advance with increasing crosssection and with. decreasing velocity against thesurface of said plate, and a wall of low heat conductivity extending opposite the baffling surface ofsaid plate to prevent escape of heat from the space in which combustion takes place in the direction away from the bafiiing surface.

12. Apparatus for burning explosive gaseous mixtures, comprising means for supplying a stream of the mixture moving revent access of with a velocity greater than the rate of propagation of inflammation of the mixture, means providing an impermeable bafiling surface against which said stream impinges and by which it is caused to spread out laterally and to advance with increasing crosssection and with decreasing velocity against said baflling surface.

13. Apparatus for burning explosive gaseous mixtures, comprising means for supplying a stream of the mixture moving with a velocity greater than the rate of propagation of inflammation of the mixture, means providing an impermeable bafliing surface against which said stream impinges and by which it is caused to spread out and to advance with increasing cross-section and with decreasing velocity against said bafiling surface, and means for preventing access of air to the spreading mixture.

14. Apparatus for burning explosive gaseous mixtures, comprising means for supplying a stream of the mixture moving with a velocity greater than the rate of propagation of inflammation of the mixture, a baffling plate against which said stream impinges and by which it is caused to spread out and to advance with increasing cross-section and with decreasing velocity against said bafiiing plate, and means for preventing escape of heat from the space in which combustion takes place in the direction away from the bafiiing surface.

15. Apparatus for burning explosive gase- .ous mixtures, comprising means for supplying a plurality of separate streams of the mixture moving with a velocity greater than the rate of propagation of inflammation of the mixture, a bafliing late against which said streams impinge an by which they are caused to spread out and to'advance with increasing cross-section and with decreasing velocity against said plate, said bafliing plate having perforations therein out of register with the impinging streams of mixture, and means providing a surface facing the baflling surface of the bafliing plate and closely adj acent thereto to co-act therewith to direct and confine the advancin mixture.

16. Apparatus foriurning explosive gaseous mixtures, comprising a hearth havlng a mlxture supply 0 ening therethrough, means for supplying t e mixture to be burned under pressure sufficient to cause it to move through the supply opening with a velocity greater than the rate of propagation of infiammation of the mixture, and a bafliing plate set close to but spaced slightly away from the hearth opposite the supply openin and adjacent portions of the hearth, sai baflhng plate serving to baffle a stream of mixture issuing fromsaid orifice and c0- acting with the hearth to direct and confine the baffled stream of mixture as it advances between the hearth and said plate with increasing cross-section and with decreasing velocity v 17. Apparatus for burning explosive gaseous mixtures, comprising a burner body or head of refractory material and of low heat conductivity, a mixture supply passage extending through the burner head, means for supplying the mixture to be burned under pressure suflicient to cause it to move through the supply passage with a velocity greater than the rate of propagation of inflammation of the mixture, and a baflling and heat-radiating plate set opposite the discharge end of said passage to battle a stream of mixture issuing from said passage and to cause the mixture to spread out against the plate and to advance with increasing cross-section and with decreasing velocity.

18. Apparatus for burning explosive gase-- ous mixtures, comprising a burner body or head of refractory material and of low heat conductivity, a mixture supply chamber adacent to but spaced off from the burner head, connecting means between the supply chamher and the burner head formed with a plurality of supply passages extending therethrough and through the burner head for the flow of the explosive mixture from the supplychamber to and through the burner head and said connecting means being formed to prevent the backward conduction of heat therethrough to such extent as would result in the walls of the supply passages adjacent the supply chamber being raised to the ignition temperature of the mixture, and a batfling and heat-radiating plate set close to but spaced slightly away from the burner head opposite the discharge ends of said passages, said bafliing plate serving to baflie the streams of mixture issuing from said passages and co-acting with the burner head to direct and confine the mixture flowing between them, said plate having openings therein out of register with the ends of the passages. i

19. A hearth comprising a receptacle; firebrick placed therein; a series of conduits passing through said receptacle and through said firebrick; a mixture supply chamber with which said conduits register; and a perforated plate in said hearth above the openings of said conduits.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

CHARLES E. LUCKE. Witnesses:

A. L. KENT,

PAUL H. FRANKE. 

